Retrograde cutting instrument

ABSTRACT

A retrograde cutting instrument and method of retrograde drilling using such an instrument. A method of forming a socket includes providing a retrograde cutter, inserting the cutter into a joint with a blade of the cutter in a straight position, pivoting the blade to a non-straight flip position, locking the blade in the flip position, and retrograde drilling a socket using the blade in the flip position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 15/349,128, filedNov. 11, 2016, which is continuation of U.S. application Ser. No.14/516,084, filed Oct. 16, 2014, now U.S. Pat. No. 9,526,510, which is adivisional of U.S. application Ser. No. 12/397,263, filed Mar. 3, 2009,now U.S. Pat. No. 8,888,781, which claims the benefit of U.S.Provisional Application No. 61/033,252, filed Mar. 3, 2008, and which isa continuation-in-part of U.S. application Ser. No. 12/114,599, filedMay 2, 2008, now U.S. Pat. No. 8,652,139, which in turn claims thebenefit of U.S. Provisional Application No. 60/915,607, filed May 2,2007, the entire disclosures of which are incorporated by referenceherein.

FIELD OF THE INVENTION

The present invention relates to arthroscopic surgical methods andinstruments and, more specifically, to an instrument and method ofretrograde repair and reconstruction.

BACKGROUND OF THE INVENTION

During arthroscopic surgery, a small incision is made in the skincovering the arthroscopic site or joint, and a cannula is inserted inthe incision to provide a pathway for surgical instruments to be placedin the joint and manipulated through arthroscopic visualization.Surgical instruments inserted through cannulas must be long and thingthis presents limitations on instruments for cutting tissue, as thediameter of the cannula ordinarily limits the width of the cuttingimplement.

Retrograde drilling of sockets and tunnels for ACL reconstruction isknown and described, for example, in U.S. Pat. No. 8,668,738, entitled“Method and Apparatus for ACL Reconstruction using Retrograde Cutter.”In such a method, sockets in bone created by retrograde cutting. Arotary cutter, mounted onto an insertion post of a guide, is insertedthrough an anteromedial portal into the knee joint. A drill pin isdrilled through the tibia and advanced until it contacts and engages acannulation in the rotary cutter on the guide. Further rotation of thedrill pin disengages the rotary cutter from the guide. The retrogradedrill pin is then retracted and simultaneously rotated for retrogradecutting of a socket or tunnel of desired depth in the tibia. A similarmethod can be used for drilling a femoral socket or tunnel. A needexists for a surgical cutting instrument that can be usedarthroscopically for retrograde drilling of tunnels or sockets in bonewithout requiring a rotary cutter and drill pin. As with allarthroscopic instruments, the surgical cutting instrument must beconfigured for insertion through a narrow cannula, but able to cut arelatively wide tunnel or socket.

A need also exists for a surgical cutter that is stable during kneearthroscopy and that provides drilling of femoral and tibial sockets ortunnels independently of one another and minimizes incisions of distalcortices and reduces intraarticular bone fragmentation of tunnel rims.

Accordingly, a need exists for a surgical drilling/cutting instrumentthat is configured to allow improved handling of the instrument within ajoint capsule, for example the knee capsule, during ACL reconstruction.A need also exists for a surgical cutter that is stable during kneearthroscopy during the cutting mode, and that also provides drilling offemoral and tibial sockets or tunnels.

SUMMARY OF THE INVENTION

The present invention provides a retrograde cutter having a cutting tippivotably coupled to the distal end of the shaft. The cutting tip iscapable of movement from a first position, which is generally alignedwith the longitudinal axis of the shaft, to a second position, which isnot aligned with the longitudinal axis, the cutting tip extending beyondthe distal end of the shaft when the cutting tip is in the firstposition.

The cutting tip is configured such that, when the cutting tip is in anarticular joint space of the articular joint, the cutting tip ispivotable from the first position to the second position for retrogradedrilling of the bone socket when the shaft of the retrograde cuttinginstrument is rotated and the retrograde cutting instrument is pulledproximally, such that the bone socket faces the articular joint space.

The present invention provides a flip retrograde cutter that creates arecipient site socket from the inside out, i.e., using a retrogradetechnique, with minimal incisions of distal cortices and reducedintraarticular bone fragmentation of tunnel rims.

These and other features and advantages of the invention will be moreapparent from the following detailed description that is provided inconnection with the accompanying drawings and illustrate exemplaryembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side view of the combined flip cutter and drill ofthe present invention;

FIG. 2 illustrates an enlarged view of the combined flip cutter anddrill of FIG. 1, with the drill end in the “straight” (or drilling mode)configuration;

FIG. 3 illustrates an enlarged view of the actuating mechanism of thecombined flip cutter and drill of FIG. 1;

FIG. 4 illustrates an enlarged view of the combined flip cutter anddrill of FIG. 1, with the drill end in the “flip” (or cutting mode)configuration;

FIGS. 5A and 5B illustrate another perspective view and an explodedview, respectively, of the combined flip cutter and drill of the presentinvention;

FIG. 6 illustrates an enlarged view of the distal end of the combinedflip cutter and drill of FIG. 1, with the drill end in the “straight”(or drilling mode) configuration;

FIG. 7 illustrates an enlarged view of the distal end of the combinedflip cutter and drill of FIG. 1, with the drill end in the “flip” (orcutting mode) configuration; and

FIG. 8 illustrates an enlarged view of the distal end of the combinedflip cutter and drill of FIG. 1, with the outer tube in a retractedposition to show the pivoting axis.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is provided to enable any person skilled inthe art to make and use the invention and sets forth the best modescontemplated by the inventors of carrying out their invention. Variousmodifications, however, will remain readily apparent to those skilled inthe art.

The present invention provides a combined flip cutter and drillinstrument that is designed to function in either a drilling mode or acutting mode. The flip cutter and drill of the present invention isprovided with a drill which has a conical, multi-blade configuration andwhich engages the shaft of the instrument to articulate between at leasta first “straight” position (for example, about parallel to thelongitudinal axis of the instrument) and at least a second “flip”position (for example, a non-parallel position relative to thelongitudinal axis of the instrument).

The flip cutter and drill of the present invention may be employed in aregular manner (when in the drilling mode or “straight” position, forexample), or in a retrograde manner (when in the cutting mode or “flip”position for example) to form a recipient socket (to accommodate anosteochondral transplant, or to allow retrograde fixation of a graftwithin two sockets, for example).

Referring now to the drawings, where like elements are designated bylike reference numerals, FIGS. 1-8 illustrate various components of acombined flip cutter and drill 100 of the present invention. The flipcutter and drill 100 of the present invention is similar to the flipretrograde cutting instrument 100 of U.S. Pat. No. 8,652,139 (thedisclosure of which is incorporated in its entirety herewith) butdiffers in that blade 5 of the flip retrograde cutter 100 is replaced bya drill or cutter 50 which is conical with a plurality of edges 52(FIGS. 2 and 4) and/or has a plurality of blades with sharp cuttingedges 52 (FIGS. 6-8), as described in more detail below, to allowdrilling both in a regular manner (in an antegrade manner) and in aretrograde manner.

The flip cutter and drill 100 includes a cannulated elongated body 10having a distal end 12 and a proximal end 13, as shown in FIGS. 1, 5Aand 5B. The body 10 of the flip cutter and drill 100 includes acannulated shaft or outer tube 11 provided at its distal end 12. Theouter tube 11 houses an inner tube or inner member 17 (as shown in moredetail in FIG. 8, for example) provided with a drill 50 having aplurality of cutting edges 52 (as shown in FIG. 2, for example). Detailsof specific exemplary embodiments of the drill 50 of the flip cutter anddrill 100 are illustrated in FIGS. 2, 4 and 6-8; however, the inventioncontemplates other shapes and geometries for the drill 50.

Drill 50 illustrated in detail in FIGS. 2, 4 and 6-8 is configured toengage the shaft or inner tube 17 of the instrument 100 and toarticulate between at least first and second positions. In an exemplaryembodiment, drill 50 engages inner tube 17 in a first or “straight”position (for example, about parallel to the longitudinal axis of thecutting instrument 100), as shown in FIGS. 1, 2 and 6. In the “straight”configuration, instrument 100 functions in the antegrade drilling mode.

In an exemplary embodiment, drill 50 engages the shaft of the instrumentin a second or “flip” position (for example, a non-parallel positionrelative to the longitudinal axis of the cutting instrument 100), asshown in FIGS. 4, 5A, 5B and 7. In the “flip” configuration, instrument100 functions in the cutting mode (for example, retrograde cutting). Thenon-parallel position shown in FIGS. 4, 5 and 7 is about perpendicularto the longitudinal axis of the cutting instrument 100; however, thepresent invention contemplates embodiments wherein drill 50 forms anyangle with the shaft (for example, an angle between about 10 to about170 degrees relative to the longitudinal axis of the cutting instrument100, as shown in FIG. 8, for example).

In use, once the drilling/cutting instrument 100 is inserted into ajoint, for example, a knee joint, the surgeon rotates (in the directionof arrow “A” of FIG. 3) actuating mechanism 60 to pivot the cuttingdrill 50 into the “flip” configuration (i.e., into a position other thanthe “straight” position), wherein the cutting tip is disposed at anangle of about 90 degrees with respect to the shaft of the instrument.The surgeon may also gradually increase or decrease the angle, asdesired and in accordance with the characteristics of the surgical site.Once the drill is articulated in the desired “flip” position, the drillis preferably locked in position by tightening the tube 11. A drillingoperation (when the instrument is in the “straight” position) or aretrograde cutting operation (when the instrument is in the “flip”position) may be subsequently carried, as desired and as known in theart.

As seen in FIGS. 5A and 5B, actuating mechanism 60 comprises a driverend 1, a nut 2, a hub 3, a retainer ring 7, two pins (a slotted springpin 9 and a pin 10), and the shaft 11. The flip cutter and drill 100 ispreferably assembled by first pressing the shaft 11 into the hub 3 untilthe shaft 11 bottoms out. The retainer ring 7 is then inserted into agroove of the hub 3 to form a first sub-assembly. Next, the inner member17 is inserted into an end of the driver end 1 and securely engagedusing the pin 10. The first sub-assembly, described above, is slid overthe assembled inner member 17 and driver end 1. Next, the drill 50 isslid into slot of the inner member 17 and securely engaged using crosspin 8. The nut 2 is then screwed onto the other end of the driver end 1.Next, the hub 3 is pulled back while advancing the nut 2 until theretainer ring 7 engages and the slotted spring pin 9 is inserted into athrough hole in the driver end 1 to secure the driver end 1 against thenut 2. An O-Ring 20 may be slid over the shaft 11, having laser etcheson its circumference. The O-Ring 20 may be used to measure depth duringretrograde drilling.

The present invention may be used to form various sockets or tunnels toallow fixation of a graft (for example, a semitendonosus allograft) orto allow replacement of osteochondral cores or implants in a retrogrademanner, to obviate inserting harvesters into the joint. For example,drilling/cutting instrument 100 of the present invention may be employedfor the formation of sockets during an “all-inside ACLRetroConstruction™” for ligament repair, which may comprise, forexample, the steps of: (i) drilling at least a femoral and tibial tunnelor socket using a retrograde drill technique employing thedrilling/cutting instrument 100 of FIGS. 1-8; (ii) providing a graft(soft tissue graft or BTB graft) in the vicinity of the sockets; and(iii) securing the graft within the femoral and tibial tunnels(sockets).

According to yet another embodiment, an exemplary method of ACLRetroConstruction™ of the present invention comprises, for example, thesteps of: (i) drilling a femoral socket; (ii) drilling a tibial tunnelor socket using a retrograde drill technique employing thedrilling/cutting instrument 100 of FIGS. 1-8; (iii) providing a graft(soft tissue graft or BTB graft) in the vicinity of the sockets; (iv)securing the graft (soft tissue graft or BTB graft) to a continuousloop/button construct comprising a button with an oblong configurationand provided with an inside eyelet that allows the passage of thecontinuous loop, preferably a suture loop; (v) passing the graft withthe button through the femoral tunnel; (vi) securing the button to thefemoral cortex once the button exits the femoral socket; and (vii)securing the graft in the tibial tunnel or socket.

Although the present invention has been described in connection withpreferred embodiments, many modifications and variations will becomeapparent to those skilled in the art. While preferred embodiments of theinvention have been described and illustrated above, it should beunderstood that these are exemplary of the invention and are not to beconsidered as limiting. It is preferred, therefore, that the presentinvention be limited not by the specific disclosure herein, but only bythe appended claims.

What is claimed is:
 1. A retrograde cutting instrument for forming abone socket in a first bone articulating with a second bone at anarticular joint, comprising: a cannulated elongated shaft having adistal end, a proximal end, and a longitudinal axis; and a cutting tippivotably coupled to the distal end of the shaft, the cutting tip beingcapable of movement from a first position, which is generally alignedwith the longitudinal axis of the shaft, to a second position, which isnot aligned with the longitudinal axis, the cutting tip extending beyondthe distal end of the shaft when the cutting tip is in the firstposition; and wherein the cutting tip is configured such that, when thecutting tip is in an articular joint space of the articular joint, thecutting tip is pivotable from the first position to the second positionfor retrograde drilling of the bone socket when the shaft of theretrograde cutting instrument is rotated and the retrograde cuttinginstrument is pulled proximally, such that the bone socket faces thearticular joint space.
 2. The cutting instrument of claim 1, wherein theshaft includes an articulating mechanism for pivoting the cutting tipbetween the first and second positions.
 3. The cutting instrument ofclaim 1, wherein the cutting tip is pivotably coupled to the shaft by across-pin near the distal end of the shaft.
 4. The cutting instrument ofclaim 3, wherein the cutting tip is at least partially received in aslot at the distal end of the shaft, the slot being sized to allowingthe cutting tip to pivot to the second position.
 5. The cuttinginstrument of claim 1, wherein the angle of the cutting tip in thesecond position is about 90 degrees.
 6. The cutting instrument of claim1, wherein the distal end of the shaft has an open end face.
 7. Thecutting instrument of claim 1, wherein, when in the second position, thecutting tip has cutting edges facing the proximal end of the shaft. 8.The cutting instrument of claim 1, wherein a locking mechanism isprovided at the proximal end of the shaft, the locking mechanism beingconfigured to lock the cutting tip in the second position.
 9. Thecutting instrument of claim 1, wherein a hub member is attached to theproximal end of the shaft.
 10. A method of retrograde drilling forforming a bone socket in a first bone articulating with a second bone atan articular joint, comprising: inserting a retrograde cuttinginstrument through a pre-formed tunnel in the first bone and into anarticular joint space of the articular joint, the retrograde cuttinginstrument comprising a cannulated shaft having a distal end, a proximalend, and a longitudinal axis, the shaft further comprising a cutting tipat the distal end, the cutting tip being pivotably engaged to the shaftand capable of movement from a straight position to a pivoted position,the retrograde instrument being inserted through the pre-formed tunnelwith the cutting tip disposed in the straight position; subsequentlypivoting the cutting tip while the cutting tip is within the articularjoint space, from the straight position, where the cutting tip isaligned with the longitudinal axis of the shaft, to the flip position,where the cutting tip is not aligned with the longitudinal axis of theshaft; and pulling the retrograde cutting instrument proximally whilerotating the shaft so that the cutting tip, in the flip position, formsthe bone socket in the first bone in a retrograde manner from thearticular joint space towards an outer surface of the first bone, andthe formed bone socket faces the articular joint space.
 11. The methodof claim 10, further comprising the step of locking the cutting tip inthe flip position after articulating the cutting tip to the flipposition.
 12. The method of claim 10, further comprising the step ofinserting a graft into the bone socket.
 13. The method of claim 12,further comprising the step of securing the graft in the bone socket.14. The method of claim 10, wherein the step of articulating the cuttingtip to the flip position includes articulating the cutting tip to abouta 90 degree angle with respect to the longitudinal axis of the shaft.15. The method of claim 10, wherein the cutting tip is pivotably coupledto the shaft by a cross-pin near the distal end of the shaft
 16. Themethod of claim 10, further comprising the step of measuring a depth ofthe bone socket during retrograde drilling.
 17. The method of claim 10,wherein the distal end of the shaft has an open end face and the cuttingtip extends through the open face when the cutting tip is in thestraight position.
 18. A method of retrograde drilling for forming abone socket in a first bone articulating with a second bone at anarticular joint, comprising: inserting a retrograde cutting instrumentthrough a pre-formed tunnel in the first bone and into an articularjoint space of the articular joint in a straight position, theretrograde cutting instrument comprising a cannulated shaft having adistal end, a proximal end, and a longitudinal axis, the shaft furthercomprising a cutting tip at the distal end, the cutting tip extendingbeyond the distal end of the shaft when the cutting tip is in thestraight position, and the cutting tip being pivotably engaged to theshaft and capable of movement from the straight position to a flipposition; subsequently, while the cutting tip is in the straightposition, articulating the cutting tip within the articular joint space,from the straight position, where the cutting tip is aligned with thelongitudinal axis of the shaft, to the flip position, where the cuttingtip is at an angle of about 90 degrees with respect to the longitudinalaxis of the shaft; locking the cutting tip in the second position whilein the articular joint space; and pulling the flip retrograde cuttinginstrument proximally and rotating the shaft so that the cutting tip inthe flip position drills the bone socket in the first bone in aretrograde manner from the articular joint space towards an outersurface of the first bone, and the formed bone socket faces thearticular joint space.
 19. The method of claim 18, further comprisingthe steps of inserting a graft into the bone socket and securing thegraft in the bone socket.